CT-guided particle implantation therapy is similar to a small nuclear bomb, in which radioisotopes are precisely placed in the tumor area through a puncture needle to kill the tumor with less damage to the surrounding normal tissue cells. For example, iodine-125, the killing range is about 1cm, and the killing effect on the tumor at the effective distance is close to that of surgical resection. However, the onset of effect is relatively slow, and the effect of continuous killing can be close to the effect of surgical treatment in 1-2 months. Tumors of a few centimeters can disappear, and the volume of larger tumors is halved with better therapeutic effects.